A role for protein kinase C (PKC) isotypes is implicated in the activation of phagocytic cell functions. An antisense approach was used to selectively deplete -PKC, both I-and II-PKC, but not ␣-PKC, ␦-PKC, or -PKC in HL60 cells differentiated to a neutrophil-like phenotype (dHL60 cells . generation, degranulation, adherence, and actin filament assembly (1-8). These functions are essential for the microbicidal activity of phagocytic cells and are also proinflammatory. PKC, a phospholipid-dependent family of serine/threonine kinases, acts in multiple signal transduction pathways. The cofactor requirements differ between different classes of PKC isotypes. Classical ␣-, -, and ␥-PKC are acidic phospholipid, diglyceride (DG), and Ca 2ϩ -dependent; novel forms ␦-, ⑀-, -, and -PKC also require acidic phospholipid and DG, but are Ca 2ϩ independent. The atypical PKC isotypes, -and -PKC, require PS but are DG and Ca 2ϩ independent (9 -14). PKC isotypes differ in their tissue distribution and localization within the cell, suggesting that each isotype plays a specific role in signal transduction.Neutrophils, monocytes/macrophages, and dHL60 cells contain multiple isotypes of PKC, including Ca 2ϩ -dependent isotypes ␣-PKC, I-PKC, and II-PKC, Ca 2ϩ
